BUFFALO, N.Y. — Religious "nones," people who do not officially associate themselves with a specific religion, are on the rise in the United States. While there are many contributing factors to this phenomenon, new research suggests one reason is the merging of politics and conservative Christian beliefs.

A study published in April in the journal Political Research Quarterly examined states that enacted policies against same-sex marriage, and found a correlation between these activities and a rising number of people who do not affiliate with a specific religion.

The study, which was co-written by University at Buffalo political scientist Jacob Neiheisel, includes the following findings:

The movement to set state constitutions against same-sex marriage, which began in 2004, made the religious right more visible to the public, especially in states considering LGBT marriage bans.

By 2010, same-sex marriage bans were in place in 29 states. These states were more likely to be evangelical and had smaller percentages of nones compared to the other states.

From 2006-10, the gap between the nones in marriage ban states and those in states with no marriage ban had been cut in half, decreasing from 3.1 percent to 1.4 percent over that period. In other words, a greater percentage of people left the church in states where the religious right is most active.

"Regardless of which measure of religious right activity in the states that we used, in states that saw contentious fights over same-sex marriage, the political presence of right-leaning religious groups tracks with the rate of religious nones. So we like to say that salient controversy is the key link that's connecting politics and religion here," says Neiheisel, PhD, an assistant professor in the Department of Political Science in UB's College of Arts and Sciences.

He adds: "You don't see people sorting along political lines or leaving churches as a result of the activity of a combination of religious and political organizations, until you start to see changes in the policy arena."

The study's corresponding author is Paul Djupe, an associate professor at Denison University. Kimberly Conger, an assistant professor at University of Cincinnati, is a co-author.

The research follows another paper co-written by Neiheisel, which collected data from individuals over time in congregations. It showed that even over short periods of time, sizable portions were leaving their churches and that a contributing cause was political disagreement. In one three-month span, 14 percent left their church; that rate grew when they examined longer periods of time.

As Neiheisel explains: "Both studies suggest a great deal of churn among religious organizations driven by political disagreement. While everyday disagreement drives people out across the political spectrum, the public salience of the Christian right specifically helped to drive up the rate of nones."

Study data was acquired from a mixture of sources, including Conger's long-running survey of experts about conservative Christian presence at the state-level, as well as her work on counts of conservative Christian interest groups at the state-level. Key outcome variables are from religious census data, collected by the Glenmary Research Center, as well as survey data from the Cooperative Congressional Election Study (CCES).